This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A195986 #23 Nov 06 2018 21:17:58
%S A195986 1,4,1,5,1,4,1,6,1,4,1,5,1,4,1,7,1,4,1,5,1,4,1,6,1,4,1,5,1,4,1,8,1,4,
%T A195986 1,5,1,4,1,6,1,4,1,5,1,4,1,7,1,4,1,5,1,4,1,6,1,4,1,5,1,4,1,9,1,4,1,5,
%U A195986 1,4,1,6,1,4,1,5,1,4,1,7,1,4,1,5,1,4
%N A195986 Exponent of the largest power of 2 that divides 5^n - 3^n.
%C A195986 Conjecture: a(n) = 1 if A090740 = 1, else a(n) = A090740(n)+1.
%H A195986 Antti Karttunen, <a href="/A195986/b195986.txt">Table of n, a(n) for n = 1..16383</a>
%F A195986 a(n) = A007814(A005058(n)). - _Antti Karttunen_, Nov 06 2018
%t A195986 Table[IntegerExponent[5^n - 3^n, 2], {n, 100}] (* _T. D. Noe_, Oct 12 2011 *)
%o A195986 (PARI) A195986(n) = valuation(5^n - 3^n,2); \\ _Antti Karttunen_, Nov 06 2018
%Y A195986 Cf. A005058, A007814, A090740.
%K A195986 nonn
%O A195986 1,2
%A A195986 _John W. Layman_, Oct 12 2011
%E A195986 Name clarified by _Antti Karttunen_, Nov 06 2018